Each year in the United States local governments spend hundreds of millions of dollars on the removal of ice and snow from public roadways. While winter snow provides a source of tourism business for skiing, snow-boarding, and other winter sports, it also presents a hazard to traffic, both vehicular and foot.
Snow removal at least allows the use of blades which can push the snow around, as the snow is loose. Ice, however, presents a much more serious removal problem. Heavy traffic, either vehicular or foot, compacts snow into ice and then prevents the use of normal snow removal equipment. Worse, the daily cycle of warming and nightly refreezing rapidly hardens the packed ice into a solid mass.
Manual removal of this ice is a tedious and time consuming job and is simply impractical for any area larger than a single sidewalk. Chemical removal poses other hazards to contaminated water supplies and vegetation, and to vehicle corrosion, wildlife and so on.
Since ice is a solid mineral, it can become quite hard and impervious to most of the usual heavy equipment used against it. Even machines which can break up ice usually do so only very slowly, one piece at a time, while causing accelerated wear and damage to the equipment.
Ice breaking machinery is known in the art. Some typical examples include rollers (drums) mounted beneath graders, the rollers having teeth projecting from them to break up the ice as they pass across it. However, the hardness of the ice and the frequent impact with curbs, gutters, rocks, parking bollards and the like mean that such teeth quickly get broken off. At that point the municipality is forced to buy an entirely new roller drum or go through a very long and expensive repair process with the roller drum. Various types of machines may be found in this area, for example, that of U.S. Pat. No. 4,304,440, designed for use on the front of equipment such as bulldozers and having staggered rows of teeth which are, unfortunately, non-standard teeth and very difficult to remove and replace.
U.S. Pat. No. 3,761,133 shows a device having offset keyways, but the teeth of that device indicate that it only functions with a counter-clockwise rotation and therefore cannot be reversed.
A slightly better solution may be found in those devices such as that sold under the name “Icebuster”, under U.S. Pat. No. 5,106,165. This device has a long roller bearing standard heavy equipment teeth, but since it allows no give across the width of the camber of a road, it fails to effectively break up all ice. In addition, the wheels are bolted and keyed to one another, not to the axle, preventing efficient assembly and disassembly. Worse, the bearings used on the axle of the device fail with extreme frequency, both due to the lack of give for camber, meaning the axle is beaten against the road surface with extreme torque and due to the choice of polymer bearings (“Tubular Blue Nylon” bearings, see reference numeral 44) for the application.
It would be preferable to provide a durable and effective icebreaking device.